Robustness of internal insulation – Installation, craftsmanship and user behavior

The present research project investigates the robustness throughout the service-life of internally retrofitted buildings. The study was conducted through laboratory and field tests, calibrated numerical simulations, and practical knowledge acquired on-site and from the users. Different insulation systems were tested. A physical robustness experiment evaluated the robustness of the insulation systems against unintentional hitting. The results revealed that hemp with lime and phenolic foam were the most robust, and aerogel was the weakest and needed the most repairs. However, no damage was observed on any systems after 5 - 8 years of daily use. A wet-cup test, focused on the role of interior paint in terms of user behavior. The experiment’s goal was to investigate the impact of incorrect paint use on the vapor diffusion resistance of the element. Based on the obtained results, simulations were made to determine the influence of the final wall paint on the diffusivity of the wall. Wet-cup tests showed that both the silicate and acrylic paint are diffusion-open, with the acrylic ones being less open, and it is unlikely that a surface can be made too diffusion-tight by conventional silicate or acrylic paint. Moreover, experiments were done regarding the microclimate between the external wall and furniture and paintings. The results did not show an increased risk of mold growth behind leather patches mounted directly to the interior surface (maximum mold index = 0.4) or behind acrylic plates mounted 1.5 cm from the surface (maximum mold index = 0.2). Finally, an evaluation of the difficulties and challenges during and after the application process was made through observations and questionnaires to the craftsmen and the residents. The results highlighted the importance of cleaning any organic matter before the application and that the installation process was relatively easy for most systems.